There are many projects related to ESP8266. However, no working Apple 2 emulator that actually run Apple 2 games. I decided to build one myself. I started this project last year.
Depends on the choice of display and keyboard, the hardware of Apple 2 emulator can be very simple. The most simplest option is video out and PS2 keyboard. The circuit only consist of a few pieces of resistors and capacitors.
When considered the availiabily and flexibility, I prefer USB for the keyborad interface.
The first design was video out and USB keyboard and the second version used LCD instead of video out.
Recently, I redesign the PCB so that it suitable for two LCD size.
1. 65C02 CPU
2. 64K Ram
3. nib, dsk,po floppy disk images
4. hdv, 2mg HDD images
5. USB keyboard
6. build-in speaker
7. simple joypad emulation use keyboard
8. Lithum Battery operated.